Table 5. Association of smoking cessation with Kidney Failure in Singapore Chinese Health Study.

Smoking Status	N	Person years	Number Kidney Failure	Unadjusted Hazard Ratio (95% CI)	Multivariable **Adjusted Hazard Ratio (95% CI)
Men
Never Smoker vs.	11705	144623	115	1.00	1.00
Quit smoking <1 year		20633	19	1.18 (0.73–1.92)	1.26 (0.77–2.08)
Quit smoking 1–9 years	1856	26472	45	2.17 (1.54–3.06)	1.83 (1.29–2.60)
Quit smoking >10 years	2333	37880	40	1.36 (0.95–1.95)	1.02 (0.71–1.47)
P trend	3301			0.002	0.22
Women
Never Smoker vs.	32152	407106	326	1.00	1.00
Quit smoking <1 year	234	2636	3	1.45 (0.46–4.50)	1.25 (0.40–3.91)
Quit smoking 1–9 years	353	3846	9	2.15 (1.55–5.82)	1.61 (0.83–3.14)
Quit smoking >10 years	445	4929	5	1.33 (0.55–3.20)	0.79 (0.32–1.92)
P trend				0.003	0.72

^*Model adjusted for age, body mass index, dialect (Hokkein, Cantonese), education level, history of physician diagnosed hypertension, diabetes, known heart disease or stroke, alcohol use and intake of ginseng.